Yarn feed fingers with removable guide inserts for knitting machines



y 1, 1962 K E. HOEFER 3,031,868

YARN FEED FINGERS WITH REMOVABLE GUIDE INSERTS FOR KNI NG MACHINES Filed Jan. 1961 5 IHVEHTOK'.

KARL. ERNEST Home,

United States Patent Ufifice 3,931,363 Patented May 1, 1962 3,031,868 YARN FEED FINGERS WITH REMOVABLE GUIDE INSERTS FOR KNITTING MACHINES Kari Ernest Hoefer, Greensboro, N.C.; H. Walter Fricke, executor of said Karl Ernest Hoefer, deceased, assignor, by mesne assignments, to Southern Mill Equipment Corporation, Charlotte, N.C., a corporation of North Carolina Filed Jan. 13, 1961, Ser. No. 82,524 6 Claims. (Cl. 66125) This invention relates to a yarn feed finger for knitting machines and more especially to a finger equipped with a strand guiding tube removably secured in one end thereof. In circular knitting machines, several of these fingers are positioned side-by-side in a manner such as shown in prior Patent No. 2,244,330, and adapted to be selectively lowered and raised to feed and withdraw the respective yarn strands from the knitting needles.

During the knitting operation, the feed finger is subjected to a relatively high degree of wear at the point engaged by the strand, and therefore, it has been found necessary to provide a replaceable tube in the finger for resisting such wear. Preferably, the body of the finger is made of metal such as steel, and the tube from a high wear-resistance material. A construction of this type permits the worn tubes to be replaced from time to time thereby prolonging the life of the finger.

In prior devices of this type, however, it has been the practice to permit the guide tube to protrude beyond the surface outline of the finger, and as a result, the protruding end or ends become entangled with the strands associated with the adjacent fingers, especially when the fingers are raised or lowered relative to one another during yarn changes. Moreover, in order to secure the protruding tube in position, it has usually been the practice to notch or otherwise irregularly shape the exterior finger surface in such a manner that the strands of adjacent fingers will become entangled therewith. For example, Patent No. 2,836,042 discloses a yarn feed finger which has been notched to accommodate a replaceable guide tube which has the ends thereof projecting above and below the exterior surfaces of the finger.

It is therefore an object of this invention to provide a yarn feed finger having a replaceable strand guide tube fixedly secured therein and positioned entirely within the surface outline of the finger.

' It is another object of this invention to provide a yarn feed finger having a replaceable strand guide tube made of high wear-resistant material, the ends of the tube being substantially flush with the opposite exterior surfaces of the finger. The invention may be employed with circular knitting machine fingers having the conventional exterior surface outline, which outline has proven highly satisfactory in avoiding strand entanglements.

It is another object of this invention to provide a yarn feed finger of the type described wherein novel means are employed for mechanically and releasably locking the guide tube against relative movement within the surface outline of the finger. Specifically, this locking means comprises a pair of spaced spring jaws at one end of the finger and between which the tube is clamped, one of the proximate jaw surfaces having a projection integral therewith which snugly fits into a notch or recess in the periphery of the inserted tube to secure the latter against relative movement.

Some of the objects of the invention having been stated, other objects will appear asthe description proceeds when taken in connection with the accompanying drawings, in which:

FIGURE l is a sectional detail view through a portion of a circular knitting machine having my yarn feed finger mounted thereon;

FIGURE 2 is an enlarged isometric view of the yarn receiving end of the finger;

FIGURE 3 is an enlarged isometric view showing the opposite side of the finger from that shown in FIGURE 2;

FIGURE 4 is an enlarged vertical sectional view taken along line 44 in FIGURE 2;

FIGURE 5 is an enlarged sectional plan view taken along line 55 in FIGURE 2;

FIGURE 6 is an enlarged isometric view of the replaceable strand guide tube;

FIGURE 7 is an isometric view similar to FIGURE 3 showing the jaws of the yarn feed finger spread apart and omitting the guide tube;

- FIGURE 8 is an isometric view of a tool which may be employed for spreading the jaws of the finger to the position shown in FIGURE 7;

FIGURE 9 is an isometric view of another tool and a guide tube supported thereby, which tool may be employed for inserting and removing a tube from between the spread finger jaws shown in FIGURE 7;

FIGURE 10 is an elevation of the end or tip of a slightly different type of yarn feed finger, and showing my invention applied thereto, and

FIGURE' 11 is a plan view of FIGURE 10.

Referring more particularly to the drawings, the numeral 10 designates the needle cylinder of a circular knitting machine, said cylinder having needles 11, the upper ends of which are adapted to cooperate with sinkers 12 in the formation of loops during a conventional knitting operation. Sinkers 12 are mounted in a sinker ring 14 which is supported as at 15 by the upper portion of cylinder 10. A latch ring 16 is pivotally secured as at 17 to the framework 18 of the machine, said latch ring being provided with a throat plate 19 which is adapted to support the lower end of one or more yarn feed fingers 20, such as hereinafter described, and in position for delivering the associated strands 21 beneath the hooks of needles.

Finger 20 is pivoted to latch ring 16 as at 23 and is adapted to be raised and lowered in a conventional manher through the combined action of a thrust bar 24 and a tension spring 25. usually provided with a number of yarn feed fingers pivoted side-by-side and adapted to be selectively operated.

' For many types of knitting operations, these fingers are equipped with replaceable strand guide tubes which protect the fingers from wear from the yarn, said tubes being mounted in the lower yarn-manipulating ends of these fingers. In the fingers employed with or without the guide tubes, care must be exercised to eliminate unnecessary protrusions from the exterior finger surfaces so as to avoid entanglement with the strand or strands of adjacent fingers. The close side-by-side spacing of the fingers and the rapid relative motion of the fingers during yarn changes requires a streamlined exterior surface free from notches or irregularities which may interrupt the strand feeding operations.

In prior attempts to equip the conventionally shaped yarn feed finger with a replaceable strand guide tube, the streamlined exterior surface of the finger has been destroyed by notches, screws and the like employed for securing the tube in position. Furthermore, such prior securing means has been used in connection with a guide tube having one or both ends thereof projecting beyond the surface of the finger. In both instances, the protrusions or projections have limited the usefulness of this type of finger due to increased work stoppage occasioned by thread entanglement.

The present invention has provided a replaceable strand guide tube in a finger having substantially the same streamlined appearance as heretofore employed for Circular knitting machines are fingers without the tube. Finger 20 is made from a relatively narrow flat metallic bar and the strand-manipu-lating end thereof (FIGURE 2) is provided with a vertically disposed front edge 30, a horizontally disposed bottom edge 31 extending rearwardly from the lower end of said front edge, and an upwardly and rearwardly inclined top edge 32 extending from the upper end of the front edge. The bottom edge 31 is stepped vertically as at 31a to provide the necesary clearance for strand passage when the end of the finger is positioned on throat plate in the manner shown in FIGURE 1. The upper end of inclined top edge 32 has extending rearwardly therefrom a horizontally disposed top edge 32a.

The above-described shape of yarn feed finger is conventional and has been widely adopted for the reason, among others, that its streamlined outer surface reduces thread entanglements and consequent work stoppages. The present invention includes means for securing a strand guide tube 34 in finger 20 without substantially changing the streamlined appearance heretofore employed.

The end of finger 20 is provided with three spaced parallel bores 36, 37 and 38, all ofwhich lie substantially in the same plane. Bore 36 is the smallest and extends between edges 31 and 32a; bore 37 is next largest and extends between edges 31 and 32; and bore 38 is the largest and likewise extends between edges 31 and '32. The end of finger 20 is provided with a slot 39 which is narrower than the diameter of either of the bores 36, 37 and 38, said slot extending along the plane of the bores so as to bisect the latter and provide a pair of spring jaws 40 and 41.

The largest bore 38 is adapted to receive guide tube 34. Tube 34 is provided with an upper bevelled end 34a adapted to be positioned substantially flush with the upper bevelled edge 32 of the finger, and also provided with a square-cut bottom end adapted to be positioned substantially flush with'the bottom finger edge 31. Preferably the ends of the tub should terminate between the opposite exterior surface outlines of the finger.

Tube 34 is also provided with a notch 34b in its outer periphery, which notch is adapted to be substantially filled by a projection 43 extending inwardly from the inner periphery of bore 38 to thereby secure the tube against movement in any direction relative to the finger 20 (FIGURES 4 and FIGURES 7, 8 and 9 illustrate the method employed in replacing tubes 34 in the finger 20. Replacement of a tube may be accomplished by first inserting a fiat point 45 of an L-shaped tool 46 (FIGURE 8) into bore 37 (FIGURE 7), and then axially rotating the point until the jaws 40 and 41 are slightly spread apart thereby relieving th spring pressure normally exerted by the jaws upon the tube and also freeing the projection 43 from the notch 34b.

With the jaws 40 and 41 thus spread apart, a wire prong 47 of another tool 48 may be inserted within the tube 34 to remove it from bore 38 (FIGURE 9). It will be observed that prong 47 has a shoulder 47a which is adapted to support tube 34 during and after removal. Obviously, a replacement tube 34 may be mounted in the finger 20 by placing the tube upon prong 47 in the manner shown and then inserting it between the spread jaws.

FIGURES and 11 show the present invention applied to a feed finger 50 having a different shape. Finger 50 has upper and lower parallel edges 51 and 52 respectively, said lower edge being stepped as at 52a. The end of finger 50 is provided with an edge 53 diagonally disposed relative to parallel edges 51 and 52. As in the preceding form of invention, the strand-manipulating end of finger 50 has suitable bores 55, 56 and 57 therein and these bores lie in a common plane. Likewise, a slot 58 substantially bisects the three bores. It will be noted, however, that bore 57 extends parallel to the diagonal or bevelled end edge 53 and has a tube 59 therein, the upper and lower ends of the tube terminating between the exterior outline surfaces defined by said upper and lower edges 51 and 52. Tube 59 has a notch 60 in the periphery thereof, said notch being filled by projection 43 to secure the tube against movement relative to the finger.

Although the present invention has been shown and described in association with yarn feed fingers employed in circular knitting machines, the invention is not intended to be so limited because the principle herein disclosed may be applied to other types of strand feed fingers.

In the drawings and specification a preferred embodiment of the invention has been disclosed, and although specific terms are employed, they are used in a generic sense and not intended for the purpose of limitation, the scope of the invention being set forth in the following claims.

What is claimed is:

1. A yarn feed finger for knitting machines comprising, an elongated bar, one end of said bar being slotted longitudinally to form a pair of spaced spring jaw members, an elongated tubular strand guide member clampingly engaged and detachably mounted between said spring jaw members, said guide member having. the opposite ends thereof terminating substantially at the opposite exterior surfaces of said bar, and interengaging means cooperating with the spring action of said jaw members and disposed between the inner opposed faces of said guide member and one of the jaw members for preventing longitudinal and rotational movement of the guide member, said means including a recess in one of the two lastnamed members and a projection on the other.

2. A yarn feed finger as defined in claim 1 wherein the proximate faces of said jaws are provided with a bore of greater diameter than the width of the slot for the reception of said tubular guide member, and wherein said recess is provided in said guide member and said projection is integral with said jaw member.

3. A yarn feed finger as defined in claim 2 wherein said bar end is substantially fiat and provided with a vertically disposed end edge and relatively long top and bottom edges, and wherein said'slot extends transversely of said edges.

4. A yarn feed finger as defined in claim 1 wherein said bar end is substantially flat and provided with a vertically disposed end edge and relatively long top and bottom edges, and wherein said slot extends transversely of said edges.

5. A yarn feed finger as defined in claim 1 wherein said bar end is substantially fiat and provided with a vertically disposed end edge, relatively long top and bottom edges, and an inclined edge between said end and top edges, and wherein said slot extends transversely of said edges.

6. A yarn .feed finger as defined in claim 5 wherein the proximate faces of said jaw members are provided with a bore of greater diameter that the width of said slot for the reception of said tubular guide member, said bore extending between said bottom and inclined edges of the bar end.

References Cited in the file of this patent UNITED STATES PATENTS 2,247,342 Brown June 24, 1941' 2,289,256 Feustel July 7, 1942 2,600,935 Spindler June 17, 1952 2,836,042 Hoefer May 27, 1958 2,896,434 McKinley et al. July 28, 1959 FOREIGN PATENTS 604,511 Great Britain July 6, 1948 

